In the lighting industry, the goal of energy efficiency precipitates a turning away from energy demanding incandescent lighting to more efficient light systems, like High Intensity Discharge (HID/HPS, MV, MH) and fluorescent (CFL, T12, T8, T5, etc.) lights, and even more energy frugal systems such as Light Emitting Diodes (LED). These light systems are difficult or, in some cases, impossible to dim with standard line dimmable systems. New dimming systems have been created to dim specialized ballast or driver powered light systems such as fluorescent and LED light fixtures. These new systems include Pulse Width Modulation (PWM), 0-1 OV and secondary resistive type controls. Instead of dimming by lowering the voltage going to the light fixture, as with common line dimming, these new dimming systems utilize a dedicated set of control wires which regulate the Ballast or Driver Output.
A new industry has originated to help commercial entities to improve their energy efficiency: Energy Services Companies (ESCo's). ESCo's are hired to actively seek the most effective way for a client to save energy and, to become more eco-friendly in every aspect possible. A major area in which energy savings can be maximized is in lighting.
ESCo's integrate high efficiency lighting into commercial campus “retrofits”, generating savings of 25-85%. But achieving these efficiency levels comes at a cost. ESCo's often encounter multitudes of light fixtures types and, each of these fixtures has varying wattage levels and light outputs.
ESCo's cannot purchase lighting in advance, because the ESCo's never know what lights systems (variety, size, wattage, lumen output, etc.) will be present, until after accessing the potential client's facility and after a detailed inventory list of the lights at the facility.
An example of an inventory list might indicate that an ESCo may need to order 50 LED recessed drop ceiling fixtures of 20 watts, and 35 fixtures at 30 watts, and 100 recessed drop ceiling fixtures that are 35 watts, and then every building in a 50 building campus may have equally random sets of lights. Creating an inventory list represents a very time consuming proposition and, if the count is incorrect or incomplete, entirely new problems arise. An ESCo's profit margin is inextricably tied to: 1) how well they replace the light to meet the lumen output; and 2) how many watts of energy are “saved” over the next 5 to 15 years.
Dimmers can lower a fixture's power consumption but it is not the answer for saving money. Even if a 40 W fixture is dimmed to 30 w to save on energy, if the dimmer is raised to max, the light will consume 40 w causing a serious monetary loss to the ESCo's profit margin. Lights “undimmed” over a period of years can require an additional 25% longer for their return on investment in the energy efficient retrofits.
All these issues prevent ESCo's from pre-ordering any light fixtures which, in turn, causes even more problems. The time-frame for installing said fixtures is affected greatly because it takes time to inventory and find the proper fixtures, and then there are further delays with ordering and shipping. If an ESCo company makes a mistake by ordering a number of fixtures that do not meet the light level expected by their client, these mistakes impact the ESCo's profit margin because the ESCo must remove and replace said lights with new fixtures so as to satisfy the customer's demands at the ESCo's expense.
What these ESCo's and other customers need is: a single product, for a given fixture type, that has the capability of replacing a multitude of existing lights; one fixture that can be limited at the high end for maximum wattage consumption (ensuring ESCo's meet their energy savings projections), while allowing for additional dimming by the end user. These lights would enable universality and nearly limitless “campus wide” energy efficiency and brightness tweaks and adjustments, and without the need to replace underperforming lights.
Today, indoor and outdoor light emitting diode (LED) light fixtures come in factory set wattage and lumen ranges. For example, standard roadway lights come in a variety of wattages, ranging from 150 watt (“W”) to 250 W to 400 W. Purchasers often order a large quantity of wattage-specific lights, and, upon delivery, find the lumen output of the light does not “fit” the needs of the lighting location. The light could be too bright, or not bright enough. Pole height, terrain, reflectivity of the surfaces around the light, light overlap, and any number of other environmental factors can mean that the industry-standard, non-adjustable LED roadway light does not meet the lighting needs of the purchaser's location. In this situation, a purchaser either has to live with the inefficiency or inadequacy of the light, or try to return the light, which may cause the purchaser to loose time and money.
While there are computer controlled wattage output systems on the market, even those systems are constrained by working with a specific wattage output (e.g. 150 W, 250 W, and 400 W). Also, computer controlled wattage output systems add extra expense in installation and/or maintenance costs. Other systems provide for replacement of lighting drivers, LED arrays, or entire LED light engines, which can create added expense in installation labor and maintenance costs. The problem is compounded in that every installation environment, especially in outdoor applications, is inherently unique and could require multiple adjustments to find a LED light fixture that “fits” the environment.
Furthermore, the same disadvantages of the current wattage output systems are present in LED light fixtures used in a variety of other applications, such as exterior, interior, and agricultural settings. Thus, there exists a need for an adjustable LED lighting fixture that is capable of achieving a wide range of wattage and lumen output with a single lighting driver.